[compiler-rt] [test] Fix sem_init_glibc.cpp test for glibc 2.36 on i386

[mgorny]

Summary

Update sem_init_glibc.cpp to apply the "newer" GET_SEM_VALUE(v) logic
to i386 if glibc is 2.36 or newer. With this glibc version, the old
macro returns "84" instead of "42".

Fixes #58079

[mgorny]

@MaskRay, @thesamesam, any chance you could reproduce/test this?

[mgorny]

Abandoning in favor of D135023.

compiler-rt/test/sanitizer_common/TestCases/Linux/sem_init_glibc.cpp

 // handled for 32-bit platforms, but since these changes are not ABI-breaking
 // they are not versioned. On newer platforms such as ARM, there is only one
 // version of the symbol, so it's enough to check the glibc version. However,
 // for old platforms such as i386, glibc contains two or even three versions of
 // the sem_init symbol, and the sanitizers always pick the oldest one.
 // Therefore, it is not enough to rely on the __GLIBC_PREREQ macro - we should
 // instead check the platform as well to make sure we only expect the new
 // behavior on platforms where the older symbols do not exist.
-#if defined(__arm__) && __GLIBC_PREREQ(2, 21)
+#if (defined(__arm__) && __GLIBC_PREREQ(2, 21)) ||                             \
+    (defined(__i386__) && __GLIBC_PREREQ(2, 36))
 #define GET_SEM_VALUE(V) ((V) >> 1)
 #else
 #define GET_SEM_VALUE(V) (V)
 #endif
 
 void my_sem_init(bool priv, int value, semval_t *a, unsigned char *b) {
   sem_t sem;
   memset(&sem, 0xAB, sizeof(sem));